Aviation最新文献_第7页

AN ALTERNATIVE APPROACH TO INDUCED DRAG REDUCTION 诱导减阻的另一种方法

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Aviation Pub Date : 2021-11-10 DOI: 10.3846/aviation.2021.15663

N. Kehayas

{"title":"AN ALTERNATIVE APPROACH TO INDUCED DRAG REDUCTION","authors":"N. Kehayas","doi":"10.3846/aviation.2021.15663","DOIUrl":"https://doi.org/10.3846/aviation.2021.15663","url":null,"abstract":"Induced drag constitutes approximately 40% of the total drag of subsonic civil transport aircraft at cruise conditions. Various types of winglets and several non-planar concepts, such as the C-wing, the joined wings, and the box plane, have been proposed for its reduction. Here, a new approach to induced drag reduction in the form of a combination of an elliptical and an astroid hypocycloid lift distribution is put forward. Lift is mainly generated from high circulation in the center part of the wing and fades away along the semi-span towards the wing tip. Using lifting line theory, the analysis shows that for fixed lift and wingspan the combined lift distribution results in an induced drag reduction of 50% with respect to the elliptical distribution. Due to its wing planform the combined lift distribution leads to a 51.5% higher aspect ratio. If structural constraints are placed, then the higher aspect ratio may affect wing weight. Although any substantial increase of wing weight is not envisaged, further study of the matter is required. Zero-lift drag and lift-dependent drag due to skin friction and viscosity-related pressure remain unaffected. The proposed lift distribution is particularly useful in a blended wing-body design.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48019522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

A BUSINESS MODEL ENABLING A PASSENGER-DISTANCE-IMPROVED LONG-HAUL NETWORK TO DECREASE TRANSPORT INEFFICIENCIES 一种商业模式，使乘客的地位得到改善的长途网络能够降低运输效率

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Aviation Pub Date : 2021-11-08 DOI: 10.3846/aviation.2021.15678

D. Steinweg, Kai-Daniel Büchter, M. Engelmann, Antoine Habersetzer, Ulrike Schmalz, A. Paul

{"title":"A BUSINESS MODEL ENABLING A PASSENGER-DISTANCE-IMPROVED LONG-HAUL NETWORK TO DECREASE TRANSPORT INEFFICIENCIES","authors":"D. Steinweg, Kai-Daniel Büchter, M. Engelmann, Antoine Habersetzer, Ulrike Schmalz, A. Paul","doi":"10.3846/aviation.2021.15678","DOIUrl":"https://doi.org/10.3846/aviation.2021.15678","url":null,"abstract":"The air transport system faces pressing challenges arising from CO2-emission reduction targets, fragmented passenger needs, and a highly competitive market environment. Aiming for a reduction of CO2-emissions in the long-haul sector, a holistic solution is suggested incorporating both operational and technological innovations in three areas: (1) changes in the air transport network structure, (2) (liquid) hydrogen as energy carrier, and (3) new aircraft and cabin design. To these ends, this paper focuses on the implications resulting from a passenger-distance improved air transport network. Demand pooling is proposed to enable higher load factors, offer more point-to-point connections for passengers, and generate new revenue sources for airlines. Based on a discussion of traditional airline business models, a seat exchange platform named “ShAirline” is proposed, allowing multiple providers to rent out cabin space. The underlying business model is evaluated considering implications for aircraft and cabin design, new passenger services, additional revenue opportunities, passenger journey times, required aircraft, as well as implications for airports. Findings indicate that the proposed seat exchange platform in conjunction with a change in aircraft ownership structure assist in removing inefficiencies across the current long-haul network and help offset barriers connected to the use of novel eco-efficient technologies.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43034465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

PREVIOUS MILITARY PILOTS AND THEIR LATER FATAL CIVIL AVIATION ACCIDENTS 以前的军事飞行员和他们后来致命的民用航空事故

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Aviation Pub Date : 2021-10-28 DOI: 10.3846/aviation.2021.15660

T. Laukkala, E. Pukkala, B. Budowle, A. Sajantila, M. Mäntysaari, H. Huhtala, A. Vuorio

引用次数: 0

SIMULATION OF EGNOS SATELLITE NAVIGATION SIGNAL USAGE FOR AIRCRAFT LPV PRECISION INSTRUMENT APPROACH EGNOS卫星导航信号在飞机LPV精密仪表进近中的应用仿真

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Aviation Pub Date : 2021-10-28 DOI: 10.3846/aviation.2021.14554

Michal Hvezda

{"title":"SIMULATION OF EGNOS SATELLITE NAVIGATION SIGNAL USAGE FOR AIRCRAFT LPV PRECISION INSTRUMENT APPROACH","authors":"Michal Hvezda","doi":"10.3846/aviation.2021.14554","DOIUrl":"https://doi.org/10.3846/aviation.2021.14554","url":null,"abstract":"Satellite navigation has become a very important topic in the air transport industry along with its application in instrument approach procedures. Recently, extracted statistical characteristics of the European Geostationary Navigation Overlay Service (EGNOS) satellite signal have been made available from real measurements in the Czech Republic. The numerical modeling approach is taken for a feasibility study of automatic aircraft control during the Localizer Performance with Vertical Guidance (LPV) precision approach based on such navigation data. The model incorporates Kalman filtering of the stochastic navigation signal, feed-back control of L-410 aircraft dynamics and the calculation of approach progress along the predefined procedure. Evaluation of the performance of the system prototype is performed using the scenarios developed with a strong interest in altitude control. The specific scenario is focused on a curved approach which offers a huge advantage of the approaches based on the Satellite-based Augmentation System (SBAS) compared to ones with the Instrument Landing System (ILS). Outputs of simulation executions are statistically analyzed and assessed against predefined navigation performance goals equivalent to ILS categories with a positive outcome.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45733717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

THE IMPACT OF DIGITALIZATION AND INTELLIGENTIZATION ON AIR TRANSPORTATION SYSTEM 数字化和智能化对航空运输系统的影响

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Aviation Pub Date : 2021-10-13 DOI: 10.3846/aviation.2021.15336

Jiezhuoma La, I. Heiets

{"title":"THE IMPACT OF DIGITALIZATION AND INTELLIGENTIZATION ON AIR TRANSPORTATION SYSTEM","authors":"Jiezhuoma La, I. Heiets","doi":"10.3846/aviation.2021.15336","DOIUrl":"https://doi.org/10.3846/aviation.2021.15336","url":null,"abstract":"This study aims to provide insights into the impact levels of digitalization and intelligentization on air transport system (ATS) in Australia, China, the US, and India. Air transport system is one of the most efficient transport systems which contains three elements: air traffic control, airport, and airlines. In modern society, the importance of digitalization and intelligentization in ATS is attached to by publics. In this study, firstly, comparative analysis is used to analyze the different states of digitalization and intelligentization level and air transport system in sample countries. Then, correlation analysis is used to study the correlation of the different impact factors with the ATS in different countries. The third one is regression analysis, it is used to analyze the relationship between ATS and the development of digitalization and intelligentization in four sample countries. At last, forecasting analysis is used to predict the future trend of digitalization and intelligentization’s impact on ATS in the sample countries in the next few years. Then, the most significant impact factors for ATS will be obtained. Also, the future development trends of ATS under digitalization and intelligentization’s impact could be forecasted by using econometric models.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46175929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

MATHEMATICAL MODEL OF HOT-AIR BALLOON STEADY-STATE VERTICAL FLIGHT PERFORMANCE 热气球稳态垂直飞行性能的数学模型

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Aviation Pub Date : 2021-10-07 DOI: 10.3846/aviation.2021.15330

N. Daidzic

{"title":"MATHEMATICAL MODEL OF HOT-AIR BALLOON STEADY-STATE VERTICAL FLIGHT PERFORMANCE","authors":"N. Daidzic","doi":"10.3846/aviation.2021.15330","DOIUrl":"https://doi.org/10.3846/aviation.2021.15330","url":null,"abstract":"Vertical flight performance of Lighter-than-Air free hot-air balloons is derived and discussed. Novel mathematical model using lumped-parameters has been used to model balloon flight dynamics and steady-state performance in particular. Thermal model was not treated as the super-heat is under the control of aeronauts/pilots. Buoyancy or gross lift, net or effective lift, specific lift, and excess specific lift were derived for a general single envelope balloon and can be applied to hot-air, gas and hybrid balloons. Rate-of-climb, absolute ceiling, rate-of-descent, and the maximum rate-of-descent or the uncontrolled terminal descent have all been modeled and sample computations performed for AX8 or AX9 FAI-class hot-air balloons. Lifting index or the specific net/effective lift have been computed treating ambient and hot air as ideal gases at various pressure altitudes and representative envelope temperatures. Drag coefficient in upward and downward vertical flights have been chosen based on best available data. Experimental scale and full-scale flight tests are suggested for more accurate estimates of external aerodynamics in vertical balloon flights. CFD computations of coupled inner- and external-flows are also recommended in future efforts. Knowledge of free balloon’s vertical performance is essential in flight planning and operational safety of flight.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49613072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

ASSESSING THE IMPACT OF THE SLOPES ON RUNWAY DRAINAGE CAPACITY BASED ON WHEEL/PATH SURFACE ADHESION CONDITIONS 基于轮毂/路径表面附着状况评估斜坡对跑道排水能力的影响

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Aviation Pub Date : 2021-10-06 DOI: 10.3846/aviation.2021.15329

Misagh Ketabdari, E. Toraldo, M. Crispino

{"title":"ASSESSING THE IMPACT OF THE SLOPES ON RUNWAY DRAINAGE CAPACITY BASED ON WHEEL/PATH SURFACE ADHESION CONDITIONS","authors":"Misagh Ketabdari, E. Toraldo, M. Crispino","doi":"10.3846/aviation.2021.15329","DOIUrl":"https://doi.org/10.3846/aviation.2021.15329","url":null,"abstract":"Aircraft braking distance is dependent on the friction between the main gear tires and runway pavement surface.Pavement texture, which is divided into macrotexture and micro-texture, has a noticeable effect upon friction, especially when the surface is wet. A risk analysis framework is developed to study the effects of longitudinal and transverse slopes on the aircraft braking distance in wet runway conditions and their influences on the probability of landing overrun accidents.This framework is operating under various water-film thicknesses, Maximum Landing Weights (MLW), and touchdown speed probability distributions for an acceptable range of longitudinal/transverse slopes and pavement texture depths.A simulator code is developed that initially computes the existing water-film thickness, as the result of intense precipitation,under aircraft main gear (depend on aircraft category) and then applies this variable as one of the main inputs to the aircraft braking distance computation. According to the obtained results, longitudinal gradient does not have a significant effect on the existing water depth on the surface although it affects the flow path length. Furthermore, 1% to 1.5% transverse slope causes rapid drainage of water from the runway surface and considerably decreases the probability of runway excursion accidents.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45498632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

SILENCE IN THE TOWER: ANALYSING THE REASONS OF AIR TRAFFIC CONTROLLERS AVOIDING VOLUNTARY REPORTING 塔里的寂静:分析空中交通管制员逃避自愿报告的原因

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Aviation Pub Date : 2021-09-29 DOI: 10.3846/aviation.2021.14540

Ilker Under, Ender Gerede

引用次数: 2

GENERATION OF AN OPTIMAL LOW-ALTITUDE TRAJECTORY FOR A FIXED-WING UNMANNED AERIAL VEHICLE IN A MOUNTAINOUS AREA 山地固定翼无人机最优低空飞行轨迹生成

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Aviation Pub Date : 2021-08-20 DOI: 10.3846/aviation.2021.13291

H. Maghsoudi, Amirreza Kosari Kosari

引用次数: 0

EFFECT OF AIR PERMEABILITY ON STABILITY OF SUPERSONIC PARACHUTE 透气性对超音速降落伞稳定性的影响